job advice?

[EastTexas]

**Sorry for the long story, but I need to unload and need advice.**

Have you ever done something stupid and then thought what was the point of that? Today I got a written warning at work because someone at one of our stores complained to HR about me being rude. (Stupid gash couldn't plug 1 cable into another in the 40 minutes I talked to her. Maybe if she could do something simple like plug a cable in, in under 40 minutes, I wouldn't have gotten so short towards the end.)

The little meeting for the warning was no big deal. Only alarming part was the document I had to sign said they could fire me if there is another incident, and here's the funny part..."or if they even percieve I might not be willing to help a customer."
Example in my mind: "Wearing that color of shirt doesn't look like you want to help the customer. You're fired."

I know this is something HR wrote, not what my boss thinks.
I know everyone is replacable, but I'm in a lucky position where few people know how to do what I do. I don't want to be specific, but there may be only a couple hundred people in the country that have learned to do what I do. So I know they don't want to let me go, I'd be fairly hard to replace.

Here's where I got stupid.
After I sat and stewed about it the rest of the day. My bright idea after my boss left, I just packed up all of my stuff and took it home. Left just an empty cubicle. Calendar, coffee mug, coasters, and glass I use for tea gone. Speakers and dock for my PDA gone, air purifier gone. I've been here over 2 years, so all the little awards and everything you get over that amount of time and put on your cubicle walls...gone.

I guess it's a little passive aggressive attempt to show who is really in charge. e.g. Don't screw with me, I won't take it. Trying to make them think I'm going to leave, when I don't really intend to. (Surprisingly I've used this tactic at another job in the past and got a raise and better schedule.)
Not sure it works for this situation anymore.

Now I'm home and reflecting on this.
Was that a really stupid move? I'm wondering if it will make things worse?
Now that I think about it more, nobody really had a choice in the whole thing. The chick complained to HR, HR has to write me up, my boss has to have me sign the thing because HR told him to, not because he wants to.

But I'm also thinking, maybe I should get another job. I doubt they ever would, but if they fired me how would I get another job after being fired for a customer service complaint? Wouldn't it also stand to reason I can't afford careerwise to stay here and allow the possibility of getting a complaint again because I wouldn't be able to get a new job.

If you made it this far thanks for reading.
Any advice, or am I too late and I've fucked it up worse?